1. Technical Field
The present invention relates to a chain for a chain-type continuously variable transmission (CVT), and more particularly to a structure of the chain.
2. Background Art
Continuously variable transmissions (CVTs) including two pulleys each having opposing conical surfaces, the distance therebetween being variable, and a flexible endless member which is wrapped around the two pulleys, are known. The rotation of one pulley is transmitted to the other pulley through the flexible endless member. At this time, varying the distance between the conical surfaces varies the wrapping radius of the flexible endless member with respect to the pulley, thereby allowing the transmission ratio to vary. Japanese Patent No. 4,372,551 (hereinafter referred to as Patent Document 1) discloses, in the specification, a chain for use as a flexible endless member of a continuously variable transmission.
The chain disclosed in Patent Document 1 is formed by coupling a plurality of chain elements. Each chain element includes a link unit and two pins. The link unit is formed by arranging a plurality of plate-shape links in the width direction of the chain, each link having an opening and placed to extend in the circumferential direction of the chain. The pins extend through the opening of the respective links at both ends of the link and come into contact with the conical surfaces at the respective ends of the pin. The interconnection between the chain elements is achieved by allowing the pin of one of adjoining chain elements to pass through the opening of the link of the other chain element.
Patent Document 1 suggests arrangement patterns of the links that can make as uniform as possible a force generated at the coupling section of the chain.